Copending U.S. application, Ser. No. 129,898, filed Mar. 13, 1980, now U.S. Pat. No. 4,272,412, issued June 9, 1981 the disclosure of which is hereby incorporated by reference into the present application, discloses novel halogen-containing cyclohexane derivatives useful as fragrance materials and their method of preparation. It has now been found that certain of these halogen-containing compounds having the structure ##STR3## wherein each of R.sub.1, R.sub.2, and R.sub.3 are hydrogen or methyl and X is halogen, are also useful in the preparation of ambrinol and homologues thereof having the structure ##STR4## wherein R.sub.1, R.sub.2, and R.sub.3 are as defined above.
Ambrinols are compounds represented by the structure ##STR5## wherein each dashed line represents a carbon-carbon single bond or a carbon-carbon double bond provided that, for any specific compound, two of the three dashed lines represent carbon-carbon single bonds. These compounds are known to exhibit interesting odor properties. Recently, .alpha.-ambrinol was shown to be a component of tincture of gray ambergris. (See. B. D. Mookherjee and R. R. Patel, Proceedings of the Seventh International Congress of Essential Oils, Kyoto, Japan, (1977), paper number 136; G. Ohloff et al., Helv. Chim. Acta, (1977), 80, 2763 and 2767; and E. Lederer, et al., Nouveau Journal de Chimie, (1977), 1, 529.)
Ambergris is a concretion formed in the intestinal tract of the cachalot whale. For centuries it has been valued by perfumers for its wet, earthy, musty, seawater-seaweed, tobacco, sandalwood, animal musk, and fecal odor. Presently, ambergris is not readily available, both because of the reduced number of sperm whales and because of efforts to protect those which remain. In fact, some countries prohibit the importation of gray ambergris and other whale products as part of a program to save the whale from extinction. Consequently, efforts have intensified to find commercial synthetic routes to prepare the ambrinols (see U.S. Pat. No. 4,163,866) and other components of ambergris, particularly .gamma.-dihydroionone. (See U.S. Pat. No. 4,129,569). However, there is no teaching in the prior art which shows or suggests conversion of the halogen-containing cyclohexanes (I) to ambrinol and homologues thereof (II) according to the low cost, efficient process of this invention.